Presser mechanism for sewing machines



A Jiuly 3, 192s. f

' A. B. CLAYTON PRESSER MECHANlSM FOR SEWING MCHINES 3 Sheets-Sheet ll gwuenhn atten ne 11 July 3, l1928. 1,615,696

A. B6 CLAYTON PRESSER MECHANISM FOR SEWING MACHINES Filed Nov. 12, 1926 :s sheets-sheet 2 July 3, 1928.

1,675,696 A. a. cLAY'roN PRESSER ME/.CHANISM FOR SEWING MACHINES Vl-"iied Nov, 12, 1926 3 sners-sheet 3 Patented July 3, 1928 t UNITEDA STATES PATENT OFFICE.

ANDREW B. CLAYTON, OF UNION, NEW JERSEY, ASSIGNOR TO THE SINGER `LIANU'IEAC- TURING COMPANY, 0F ELIZABETH, NEW JERSEY, A CORPORATION OE NEW JERSEY. y

PRESSEE `MECHANISM FOR SEWING MACHINES.

Application :tiled November 12, 1926. Serial No. 147,893.

This invention relates to sewing machines and more particularly to the presser mechanism of clamp-feed or top-feed sewing miition feed-dog omitted; the upper feed-foot,v

acting to slide the work over the throatplate duringl the feeding stroke. Y

With feeds of these types it is customary to provide a presser-foot to hold the work under control when released by the feeding means. Such presser-foot is commonly c arried by a spring-pressed presser-bar which latter is so connected to the lifting mechanism for the upper feed-foot that the presser-foot is lifted by upward reaction of such mechanism against the presser-bar when the feed-foot is lowered into engage ment with the work, and the presser-foot is lowered into engagement with the work when the upper feed-foot is lifted; the presser-foot and feed-foot being alternately subjected t0 the heavy pressure of the presser-bar spring. This alternate liftingV and lowering of the two feet produces an objectionable hammering as the speed of the machine is increased and limits the effective speed of the machine.`

Clamp-feed machines as heretofore constructed have another objectionable characteristic, residing in the chopping actionof the top and bottom feed-dogsupon the chain of stitches, when chaining off, it `being necessary to arrange portions of both top and bottom feed-dogs in rear of the presser-foot to feed the chain when the presser-foot is f lifted. This chopping action mutilates the chain and limits the speed at which the machine will chain off.

It is an object of the present improvement to reduce the hammering action of a topfeed and presser-mechanism and to provide for chaining off freely at higher speeds.

To these ends provision is made for allowing the presser-foot to remain continuously in engagement with the work during the sewing. The presser-footy is preferably carried by the lower part or section of a'two-part presser-bar, between which parts a light expansion spring is interposed. The usual manual lifting mechanism is applied to the lower presser-bar section, which may be called the main presser-bar, while the automatic top-feed .and presser-lifting mecha-nism is applied to the upper section of the presser-bar,- Which may be termed an auxlhary presser-bar. The result is that the presser-foot is not automatically liftedfrom the work but remains continuously in engagement with the work during the sewing, being pressed upon ythe work by the heavy pressure of the usual presser-bar spring when the feed-foot is lifted forits return stroke, and being relieved of such heavy pressure but still under the light pressure of the expansion spring during the feeding stroke. y

Only one feed-dog or member,preferably the lower, is arranged directly in rear of the sewing point to engage and feed the chain which is thus not subjected to the chopping action of' two coacting toothed feed-members. The presser-foot is preferably extended rearwardly over the lower feed-dog While the upper feed-dog or foot is disposed wholly at one sideof the line of sewing.A I The relief of the pressure during the feed-strokeavoids an objectionable drag of the presser-foot uponthe work. Also the load on the upper-feed mechanism is reduced since `it is not called upon to overcome the inertia of and reciprocate the main presser-bar.v The present improvement maintains a heavy pressure on the presserfoot when neededto control the work and relieves the presser-foot of such pressure durin the feed but does not lift the presserfootl rom the work. lIn the accompanying drawings, Fig. 1 is an end elevation of a sewing machine embodying theinvention. 'Fig 2 is a` sectional view of the head at the end of the bracketarm in the plane of the needleand presserbars. Fig. 3 is a section on the line 234-3, Fig. 1. Fig. 4 is a plan view of themachine bed. Fig. 5 is a rear elevation of the machine. Fig 6 is a top Vplan view, partly in section, of the mechanism at the free end of the bracket-arm, and Fig 7 is a top plan viewV of the top-feed-foot and presserfoot showing their cooperative relation with the bottom feed-dog and needle.

The invention is shown as embodied in a sewing machine having a frame comprising a bed 1, standard 2 and bracket-arm 3 terminating in the'head 4. A at clothplate'5 is supported above the bed 1.A

The stitch-forming mechanism comprises the usual reciprocating'needle 6 and threadcarrying looper 7. The needle 6 is carried by the needle-bar 8 which is actuated by the link connection 9 with the crank-arm 10 on the oscillatory needle-driving shaft 11. The looper 7 is actuated from the lower mainshaft 12 by mechanism constructed substantially in accordance with the disclosure of the patent to DeVoe, No. 1,100,124, of June 16, 1914.

The particular' machine illustrated is provided with clamp-feeding mechanism comprising a lower four-motion feed-dog 13 and an upper four-motion feed-foot- 14.- The feed-dog'13 isv mount-ed on the feed-bar 15 pivotally supported at 16 on the feed-rocker 17 journaled at 18 on the bed 1. Feed-lift movements are imparted to the feed-bar by means of the eccentric 19 on the mainshaft 12; which eccentric is embraced by the strapped end of a slide-pin 20 working in the feed-bar. Feed-advancing movements are imparted to the feed-rocker 17 by means of the adjustable eccentric 21 on the mainshaft 12, which eccentric is connected by the pitman 22 to the pin 23 carried by the feedrocker 17.

The upper four-motion feed-foot 14 is carried by the feed-bar l24 which is pivotally hung from a pin 25 on a block 26 slidably' mounted on the bearing bushing 27 in which and the lower bushing 27 the main presserbar 28 carrying the presser-foot 29 is slidably journaled. The bot-tom feed-dog 13 has a portion 13a. Fig. 7, directly in rear of the needle 6 and a portion alongside the needle. The presser-foot 29 is extended in rear of the needle so as to work directly over the portion 13 of the bottom feeddog. The top-feed member 14 is wholly at one side of the line of stitching and does not bear upon the stitched zone of the work. Feed-and-return movements are imparted to the feed-bar 24 by means of the link-connection 30 with the arm 31 fixed to the rockshaft 32 having fixed to its rear end a crankarm 33 connected b a link 34 to the slotted arm 35 ofthe fee -rocker 36 -journaled in the bearings 18l and connected to the feedrocker 17 by means of an extension of the pin 23, Fig. 5, which enters a slide-block 37 fitted to the slot 38 in the feed-rocker 36, whereby the feed-rockers 17 and 36 are moved in unison.

Feed-lift movements are imparted to the block 26 and feed-bar 24 by means of a toggle device comprising toggle links 39, 40.

VToggle-link 39 is of angular or bellcrank ormand is connected at its lower end to the pin 41-on the block 26. At its upper end the toggle-link 39 is connected by the screwin 42 to the lower end of the toggle-link 40.

oggle-link is hun from the lateral pin 43 on the block 44Y xed to the auxiliary presser-bar vor presser-bar section 45 journaled in the sleeve 27 in alinement with the main presser-bar or lower presser-bar section 28. A weak Vexpansion coil-spring 46, F ig. 2, housed in a bore in the upper presser-bar section 45 is inter osed between the presser-bar sections 28 an 45 and serves as an auxiliary presser-bar s ring to maintain the presser-foot 29 lighty in engagement with the work when the upper presser-bar section 45 is lifted against the pressure of the heavy leaf-spring 47 by the straightening of the toggle links 39, 40; bringing the pivot points 41, 42 and 43 into substantial alinement, as shown in Figs. 1, 2 and 3. The auxiliary presser-bar or upper presserbar section 45 1s held against turning movements by a forked extension 48 of the block 44 which embraces the needle-bar bearing bushing 49, Figs. 1 and 2.

The toggle-links 39 and 40 are actuated by a link 50 which is connected at 51 to the toggle-link 39 and atpits other' end is adjustably comiected at 52 to theslottc'd arm 53 fixed to the rock-shaft 54 to which is also fixed the in 55 entering the sleeve 56 pivoted on tiie crank-pin 57 on the rearward extension of the crank-arm 10 fixed to the shaft 11. Y

It will be understood that during the feeding stroke of the .feed-dog 13 and feedfoot 14, the work is clamped between them under the reactionary pressure of the leafspring 47 and that the presser-foot 29 is not lifted from the work but is pressed lightly thereagainst by the light spring 46. During the return movement of the feed-dog 13 and feed-foot 14 the leaf-spring 47 forces the auxiliary presser-bar 45 down upon the main presser-bar 28 and the full pressure of the leaf-spring 47 is transmitted to the presser-foot 29-to hold the work under control before released by separation of the feed-dog 13 and feed-foot 14. It also vfollows that the work is firmly clamped between the feeding elements 13, 14 before the heavy pressure of the presser-foot 29 on the work 1s reduced. In' chaining off, the portion 134of the bottom feed-dog engages. the chain 4of stitches issuing vrearwardly from' the sewing point and feeds such chain under the light pressure of the presser-foot 29 which is not lifted during the feeding stroke of the feed-members 13, 14. There is consequently no chopping or mutilation of the chain.

The presser-foot 29 and feed-foot 14 may be manually lifted by the usual hand camlever 58 or treadle-controlled lever 59 which operatively engage the slide-block 60 having spaced lugs 61 slidably 'embracing the presser-bar section 28 to which is fixed, be-

f means for reducing the pressure of the presser-foot upon the work during the feeding stroke of the feed-foot, without lifting the presser-foot from the work.

2. In a sewing machine, the combination with a four-motion upper feed-foot, of a presser-foot, heavy and light springs pressing the presser-foot uponl the work, and automatic means for lifting the pressure of the heav spring off of the presser-foot during the eeding stroke of the feed-foot.

3. In a sewing machine, the combination with an upper four-motion feed-foot, of a presser-bar constructed in two parts with a light expansion spring interposed between such parts, a heavy spring pressing upon the upper part of the presser-bar, a presser-foot carried by the lower part of the presser-bar, and automatic means for lifting the upper part of the presser-bar to relieve the pressure of the heavy spring on the lower presser-bar part during the feeding stroke of the upper feed-foot.

4. In a sewing machine, an upper feedfoot, an upper feed-bar, a presser-bar having two relatively movable parts with a light expansion spring actingfbetween such parts, a heavy spring pressing downwardly upon the lower presser-bar part through the upper presser-bar part, means reacting downwardly against the feed-bar for periodically lifting the upper part of the presser-bar against the force of said heavy spring, said means also serving to periodically lift the feed-bar, and means for imparting feed-andreturn movements to the feed-bar.

5. In a sewing machine, in combination,

an upper four-motion feed-bar, va feed-foot carried by said feed-bar, a presser-bar, a presser-foot carried by said presser-bar, a heavy spring exerting downward pressure upon .said presser-bar, means for raising and lowering said feed-bar and periodically transferring the pressure of said spring from said presser-bar to said feed-bar, a light spring acting on said presser-bar to retain the presser-foot in engagement with the work when the pressure of the heavy spring is shifted to the feed-bar, and means for imparting feed-and-return movements to the feed-bar.

6. In a sewing machine, an upper feedfoot, an upper feed-bar, a presser-foot, a main presser-bar carrying said presser-foot, a light spring acting upon the main presserbar during the sewing to maintain the presser-foot continuously in engagement with the work, an auxiliary presser-bar movablek independently-of the main presserv bar and actingat times to exert increased downward pressure upon the main presserbar, a heavy spring acting upon said auxiliary presser-bar, means reacting upwardly against said auxiliary presser-bar and heavy spring for forcing said feed-foot upon the work, said means also acting at another period of the feeding cycle to lift the feedfoot and permit the pressure of the auxiliary presser-bar to be transferred to the main presser-bar, and means for imparting feedand-return movements to the feed-bar.

7. In asewing machine, Lthe combination with stitch-forming mechanism including a reciprocating needle, of feeding mechanism including top and bottom four-motion feedmembers of which only the bottom feedmember enga-ges the work directly in rear of the needle, and a spring-pressed presserinember having a portion disposed in rear of the needle above the bottom-feed, and means for reducing the downward pressure of the presser-foot during the feeding stroke of the feed-members, without lifting the presser-foot.

In testimony whereof, I have signed my name to this specification.

ANDREW B. CLAYTON. 

